This invention relates in general to heat exchangers and in particular to a new and useful plastic heat exchanger having two interconnectable parts.
The subject of the invention is a double-walled plastic heat exchanger having two mutually spaced plate walls with mutually parallel cross webs connecting the two mutually spaced plate walls, together a multiplicity of longitudinal channels is thus formed for a heat transfer medium. The channels have open ends communicating with distribution and collection elements fastened to at least one face of the heat exchanger plate. These elements in turn are provided with connections for the inlet and outlet of the heat transfer medium.
Known heat exchangers of a similar kind, usable e.g. as solar collectors or floor heating elements depending on material and design, have distribution and collection tubes which are perforated according to the channel pitch of the heat exchange plate and provided, in the area of a row of performations, with connecting flanges which, overlapping the plate face, are welded to the plate. Apart from the complicated design of these distribution and collection tubes, it has turned out that it is rather difficult to connect these tubes to the plate in a manner which is leak and pressure proof. In addition, the cross section of these tubes and, hence, the I.D. of the distribution and collection channel, must always be greater than that of the longitudinal channels of the heat exchange plate, which are only few millimeters wide. This causes undesirably high heat transfer medium pressures in these distribution and collection channels. It has also been suggested to design the performated distribution and collection tubes as a single piece, divided only by one cross web, and to weld these tubes to the edge of one plate face while a bypass channel is welded to the edge of the other plate face. These reverse flow heat exchangers must be joined together at the respective building site by welding adapter tubes to their distribution/collection tube which is open at both long plate sides to form the collector or absorber unit usually consisting of many individual heat exchangers, this is not only cumbersone, but in most cases gives no assurance of a leak and pressure proof connection.